400EX 400X 89mm Hi Comp Big Bore Kit Race Gas 12.5:1 Piston +4 Rebuild 440cc Kit

Unleash Power: 400EX 400X 440cc Hi-Comp Big Bore Kit - Race-Ready Performance

Rev up your ride with the 400EX 400X 89mm Hi Comp Big Bore Kit, a race-inspired powerhouse designed for serious riders. Transform your Honda 400EX, 400X, or XR400R into a high-performance machine with this complete bolt-on kit—no machining required!

Key Features:

• Incredible Power: Boost your engine's displacement to 440cc with a Wiseco 89mm forged piston, delivering an impressive 12.5:1 compression ratio for both pump and race gas.
• Durable Components: Our kit includes nitride-coated piston rings and a chrome wrist pin, ensuring longevity and optimal performance.
• Enhanced Reliability: The Talon Titanium cylinder head stud kit comes with a LIFETIME WARRANTY*, while the heavy-duty cam chain conversion is thicker and offers superior strength compared to OEM.
• Complete Package: You’ll receive everything you need in one box, including the Cometic big bore top-end gasket kit and MLS head gasket, and new NGK spark plug for a seamless installation.
• Guaranteed Performance: Each kit is backed by a 1-year warranty*, so you can trust in the quality and durability of your upgrade.